反应型香豆素探针的合成及其对废水中汞离子的检测

以间苯二酚为原料合成了一种新型反应型的香豆素二硫缩醛荧光探针(L1),并通过结构确征。在pH 6.15～9.96时,探针L1可以高选择性对Hg~(2+)进行荧光检测,检测限低至1.6 nmol/L;同时提出了L1对Hg~(2+)的传感机制,并通过核磁研究证实。在紫外线灯下,肉眼可检测到荧光的颜色变化。实际应用研究表明,荧光探针L1能应用于真实水样中Hg~(2+)的痕量检测。     

Hg2+探针的合成、光谱性能及生物应用研究

设计合成并表征了一种罗丹明类Hg~(2+)探针,对其识别性能进行了研究。检测了探针的紫外吸收光谱及荧光发射光谱,结果表明探针对Hg~(2+)具有较好选择性和灵敏度。探针与Hg~(2+)结合后,观察到吸光度、荧光信号及溶液颜色都发生改变。通过Job′s曲线研究发现Hg~(2+)和探针配合的计量比为1∶1。理论计算表明,探针结构中的S原子和羰基O原子与Hg~(2+)进行配位,诱导内酰胺环打开。将10μmol/L的探针作用于细胞时,存活率约为90%。10μmol/L探针在细胞中几乎无荧光,与Hg~(2+)孵育后可观察到细胞内的荧光明显增强,探针具有很好的细胞膜通透性。在小鼠腹腔内注射探针(400μL×400μmol/L),拍照未发现荧光,在同一位置注射Hg~(2+)后,捕获到明显荧光信号。结果表明,探针具有优良的性能,在生物体染色和标记以及疾病的早期诊断方面都具有潜在的应用价值。     

以表吲哚二酮为母体的Hg~(2+)荧光探针合成

以表吲哚二酮为母体,制备出了对Hg~(2+)具有特定响应的比率型荧光探针。该荧光探针对Hg~(2+)的响应快、选择性高,且紫外吸收和荧光发射均落在可见光波长区,裸眼可见。通过工作曲线,可以计算被检测Hg~(2+)的浓度,因此实现了Hg~(2+)检测的方便性、快捷性。     

5-苯基-2-邻甲苯-2H-1,2,3-三氮唑-4-羧酸乙酯的结构性质及其罗丹明衍生物检测汞离子

应用计算化学的方法研究了5-苯基-2-邻甲苯-2H-1,2,3-三氮唑-4-羧酸乙酯(EPTC)的结构及理论光谱,并与实验测定结果相比较;再将EPTC与罗丹明B合成了新化合物REPTC,采用紫外吸收和荧光光谱法测定了REPTC与16种金属离子的相互作用。实验结果表明:在pH 7.4的N,N-二甲基甲酰胺(DMF)-水溶液中,REPTC在2.33×10~(-5)～4.00×10~(-5) mol/L的浓度范围内,仅对Hg~(2+)有高选择性的响应,表现为在577 nm处出现一个新的发射峰且强度显著增大,同时肉眼可观察到明显的颜色变化。结合电喷雾质谱及理论计算表明:Hg~(2+)的存在使得REPTC分子中罗丹明的螺环结构从闭环转为开环,可与Hg~(2+)形成物质的量比为1∶2的新配合物。荧光成像实验表明:REPTC可成功标记HeLa细胞中的Hg~(2+),进而可开发用于生物体系中Hg~(2+)的测定。     

一种戊二醛-壳聚糖非共轭荧光聚合物传感器检测水样中汞离子

开发了一种新型、快速的荧光传感器用于水样品中Hg~(2+)的检测。合成了一种戊二醛-壳聚糖非共轭荧光聚合物(GCPF),在370 nm波长激发下,于455 nm波长处产生荧光。研究发现,汞离子(Hg~(2+))的存在能使GCPF荧光被猝灭。传感器对Hg~(2+)的检测线性范围是0. 8～30μmol/L,检测限为85 nmol/L。该方法灵敏度高、线性范围宽、成本较低、操作方便、响应迅速(约1 min),对其他金属离子具有很好的选择性。将其应用于实际水样中Hg~(2+)检测时也得到了令人满意的结果。     

罗丹明类荧光探针的合成及其对Hg~(2+)的识别研究

以罗丹明B、水合肼及2'-羟基苯乙酮等廉价化合物为原料,经过简单的缩合反应得到可识别Hg~(2+)的荧光探针L,其结构经1HNMR、13CNMR以及HR-MS表征。光谱性能研究表明,探针L在Et OH-H2O(V(Et OH)∶V(H2O)=4∶1,p H 7.0,20 mmol/L HEPES)体系中,对Hg~(2+)具有优异的识别能力,两者的配合比为1∶1,且识别过程可逆。     

基于罗丹明B的有机荧光探针合成及Cu~(2+)检测

基于罗丹明B合成了两种有机荧光探针用来检测Cu~(2+)。以罗丹明B与3-甲氧基苯酰肼、水杨酰肼为原料合成了两种探针,命名为Rh1、Rh2,分别与Cu~(2+)以及其它金属离子溶液反应,观察溶液的颜色变化,分别测定其紫外及荧光吸收光谱。Rh1、Rh2加入铜离子溶液后,溶液由无色到粉红色的显著颜色变化,与其它金属离子比较在400～700nm有较明显的紫外-可见吸收和荧光增强。两种荧光探针能够有效的跟Cu~(2+)结合,从紫外-可见吸收光谱和荧光光谱可以看出此探针显示出选择性的、敏感的荧光增强反应,表现出对Cu~(2+)良好的选择性。     

2,5-二羟基苯甲醛缩肼席夫碱的性质和研究

设计和合成了一种双席夫碱。利用红外光谱对其结构进行表征,研究了其在不同溶剂中的紫外吸收光谱和荧光光谱,探究了过渡金属离子对紫外和荧光光谱的影响及聚集诱导发光(AIE)性质。结果表明,在不同溶剂中化合物的紫外光谱发生蓝移,荧光发射强度随溶剂极性增加强度减弱,且发生红移。通过紫外光谱和荧光光谱说明Fe~(3+)、Cu~(2+)在溶液中和化合物分子发生较强的相互作用,生成稳定配合物。同时该化合物没有表现出明显的AIE性质。     

荧光猝灭法快速检测水样中的汞离子

快速、灵敏定量环境水样中的汞离子(Hg~(2+))对水质监测和人体健康有十分重要的意义。本研究利用富含胸腺嘧啶碱基(T)的DNA,发展了一种灵敏的荧光分析法,实现了Hg~(2+)的快速检测。首先,在DNA两端各修饰一个发光基团(6’-FAM)和猝灭基团(BHQ1)。在Hg~(2+)存在时,相对的两个T碱基与Hg~(2+)通过金属配位形成T-Hg~(2+)-T结构,从而使ss DNA形成ds DNA,DNA的结构变化会使发光基团和猝灭基团距离靠近,从而猝灭发光基团的荧光,实现对水样中Hg~(2+)的定量分析。对Hg~(2+)的检测浓度在10～100n M范围内呈线性相关,所用方法检出限为2.0n M(MDL=3σ/S)。     

5,10,15,20-四(4-羧基苯基)卟啉(TCPP)检测水体痕量Hg~(2+)的研究

由于羧基卟啉在水中良好的溶解性及对Hg~(2+)的高亲和性,利用5,10,15,20-四(4-羧基苯基)卟啉与Hg~(2+)反应前后的荧光特性变化,实现水体Hg~(2+)的痕量检测。结果显示,该探针与Hg~(2+)具有良好的配位性,且检测前后体系出现的颜色变化具有可视性。在中性条件下,四羧基卟啉荧光被Hg~(2+)猝灭,荧光强度与汞离子浓度之间存在良好的指数函数关系,相关系数为0.998。因此,5,10,15,20-四(4-羧基苯基)卟啉可作为一种高效、可靠的探针用于水体中Hg~(2+)的痕量检测。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。